Patient mobility is an integral part of many patient care regimens in high acuity care environments. As part of the recovery process, patients are encouraged to periodically stand up and make short trips to the window, the bathroom, etc. Lack of patient mobility can result in physiologic complications such as deep vein thrombosis, infection and an overall prolonged recovery process.
Continuous monitoring is preferably provided during these patient mobility events. Thus, it is preferable to allow a patient to be continually monitored while not physically connected to a local/bedside monitor. Such continuous monitoring requires a reliable system for data transfer so that monitoring information is not lost or degraded. Further, if a patient is having a problem, it is desirable to know as soon as possible. For example, notice of an alarm regarding a patient condition should not be lost or delayed when the patient is moving, which could lead to a delay in care that can have a negative outcome for the patient.
While wireless data transmission can offer the advantage of substantially continuous monitoring, it is not as reliable as a direct connection. Objects may emit fields or signals that interfere with the ability of a wireless system to accurately transmit data in certain frequency ranges. For example, the Wi-Fi band, e.g., the 2.4 GHz band, is prone to collision and other interferences causing dropped packets. Further, there are often gaps in Wi-Fi networks where coverage is weak or non-existent.
Many prior art devices use the Wireless Medical Telemetry Service (WMTS) frequencies—608-614 MHz, 1395-1400 MHz, or 1429-1432 MHz—for the wireless transmission of data. The WMTS frequencies are fairly reliable because they are relatively low on the frequency spectrum and, perhaps more importantly, because they are restricted-use frequency ranges so that interference is less of an issue. However, information transmission via WMTS is slow and less practical compared to transmission via the Wi-Fi band.
As patient monitoring devices begin leveraging wireless infrastructure, such as Wi-Fi networks, it is important to make sure that the quality of patient monitoring is not degraded. With Wi-Fi connections, the quality of service and benefits of the dedicated spectrum provided by WMTS is lost. Further, with the shorter signal range and the necessity of switching between access points to stay connected, patient monitoring devices utilizing Wi-Fi must be carefully designed to ensure that monitoring quality remains high.